Circuit controlling device



April 26, 1938. H 2,115,078

CIRCUIT CONTROLLING DEVICE Filed June 9, 1933 2 SheetsSheet l 51 5o 45ea 15 17 1a 60 64 59 70 63 .5 77 6? 66 76 '11 Q4 10 Mk5 0 O 7 9 k 13 I O7 69 I April 26, 1933- c. w. KUHN 2,115,078

CIRCUIT CONTROLLING DEVICE Filed Jun 9, 1933 2 Sheets-Sheet 2 v a .11777 d? 76 11169 7175 r Patented Apr. 26, 1938 CIRCUIT CONTROLLINGDEVICEClarence W. Kuhn, Milwaukee, Wis., assignor to Cutler-Hammer, Inc.,Milwaukee, Wis., a corporation Y of Delaware This invention relates toApplication June 9, 1933, Serial No. 675,011

9 Claims.

electric circuit consome instances this device has been foundobjectionable due to the fact that it is necessary to employ a signallamp to indicate tripping of the overload mechanism.

The present invention has among its objects to provide a refrigeratorcontroller having a manual control adapted to indicate tripping of theoverload mechanism, and adjustable to effect temperature control,defrosting and overload reset.

Another object is to provide a control device of the aforementionedcharacter having a rotatable temperature control knob which is movedaxially out of a given normal position to indicate tripping of theoverload mechanism and which is returnable to such position to effectresetting of the overload mechanism.

Another object is to simplify and generally improve the construction andoperation .of refrigerator control devices and to provide improvedmanual control means therefor.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawings illustrate certain embodiments of theinvention which will now be described, it being understood that theembodiments illustrated are susceptible of modiflcation withoutdeparting from the spirit and scope of the appended claims.

In the drawings,

Fig. 1 is a plan view of a control device embodying the invention, acover for the enclosing casing of the device being removed;

Figs. 2, 3 and 4 are sectional views taken substantlally on lines 2-2,3-3 and 4-4, respectively, of F18. 1;

Fig. 5 is a fragmentary sectional view similar to that shown in Fig. 2,but illustrating certain of .the operating parts in another position:

Fig. 6 is a sectional view on line 6-6 of Fig. 2;

Fig. 7 is a sectional view on line 1-4 of Fig. 8 is an isometric view ofa movable switch element associated with the I'lg. 1;

switch unit shown in Fig. 9 is an isometric view of the complete switchunit together with a diagrammatic showing of the circuit connectionstherefor;

Fig. 10 is a sectional view on line Ill-10 of Fig. 1, and

Fig. 11 is a sectional view illustrating a modifled form of manualcontrol embodying the invention.

The controller illustrated in Figs. 1 and 2 includes an elongatedbox-shaped housing I hav- 10 ing a switch unit 2 and a fluid conditionresponsive unit 3 mounted therein. As hereinafter set forth, the switchunit 2 is controlled by the fluid condition responsive unit 3 to effectstarting and stopping of the refrigerator and the unit 15 3 is shopadjusted to provide predetermined normal cycles of operation of therefrigerator and is also adjustable by rotation of a knob 4 mounted onthe housing I to provide for modification of such cycles. Also ashereinafter set forth the switch unit 2 has an overload mechanismassociated therewith which is responsive to effect stopping of therefrigerator and the knob 4 is movable axially to control such mechanismand to also indicate response thereof under overload conditions.

The switch unit 2 includes an insulating block 5 having stationarycontacts 6 and I mounted upon the front end thereof to be bridged by apair of cooperating movable contact members 8 w and 9. As shown in Fig.9 one end of movable contact 8 cooperates with stationary contact 6 andthe opposite end thereof is pivotally mounted at l0 upon an invertedL-shaped supporting member I l which is secured to the upper face of 5insulating block 5 by a screw l2. Also as shown in Fig. 9, the movablecontact 9 is mounted upon an insulating support l3 and one end thereofcooperates with stationary contact I while the opposite end thereofcooperates with movable con- 40 tact 8 at a point to the right of pivotIII.- Insulating support I3 is slidable within a recess 14 in theunderside of insulating block 5 and contact 9 is mounted between spacedupwardly projecting lugs 15 and it on the front end of said support. 4.5As shown in Figs. 6 and-8, contact 9 has a stirrup II secured to therear face thereof which straddles lug i6 and a coil spring I8 held undercompression between the inner end of said stirrup and said lug serves tobias said contact towards said lug. Insulating support I3 has anoverload responsive mechanism associated therewith for normally holdingthe same in the position shown in Fig. 6 against the action of a springI! which engages an upwardly projecting lug 20 on the rear end of saidsupport. As is apparent, with the support 13 held in the position shownin Fig. 6 spring l8 acts to yieldingly hold movable contact 9 inengagement with stationary contact l and movable contact ll and to alsoyieldingly hold the latter contact in engagement with stationary contact5.

The overload responsive mechanism associated with insulating support i3includes a spring latch 22 secured to said support and arranged tocooperate with an electro-thermal device 23 mounted upon insulatingblock 5. Electro-thermal device 23 includes an electric heater 24 ofhelical form arranged within a recess in the upper face of insulatingblock 5, a tubular member 25 fixed within an opening in said block andhaving its upper end surrounded by said heater and a ratchet pin 25located within said tubular member. The upper end of ratchet pin 26 isconnected to tubular member 25 by a solder connection 2? and the lowerend of said pin is supported upon a plate 28 fixed to base 5 by a screw29 and is provided with an enlarged toothed head 35 which cooperateswith latch 22 to normally hold the insulating support l3 in the positionshown in Fig. 6 against the action of spring I9. As shown in Fig. 9, theheater 24 has one terminal connected to contact 6 and the other terminalthereof is connected to a terminal plate 3! fixed to the upper face ofinsulating base 5 by a rivet 32 shown in Fig. 2. A line terminal 33 isalso mounted upon the upper face of insulating base 5 and contact I issecured to base 5 and connected to said terminal by a screw 35.

The refrigerator motor is illustrated at M in Fig. 9 and the supplycircuit therefor is indicated by lines L L Line L is connected toterminal 33 and one terminal of motor M is connected to terminal plate3| while the opposite terminal thereof is connected directly to line LWith the insulating support l3 latched in the position shown in Fig. 6the motor circuit is normally established from line L to terminal33'through screw 34 to stationary contact I through movable contacts 9and 8 to stationary contact 5 and through heater 24 and terminal plate3| to one terminal of the motor M. Upon given overload conditions in themotor circuit, heater 24 acts to fuse the solder connection 21 of theelectrothermal device 23, and as is apparent the toothed wheel 39 ofsaid device is then released and insulating support I3 is movedforwardly under the action of spring I9 to move contact 9 out ofengagement with stationary contact I and movable contact 8 forinterruption of the motor circuit. As will now be set forth, the knob 4is adjustable'axially to effect resetting of the aforedescribed overloadresponsive mechanism and to also effect tripping thereof at will fordefrosting of the refrigerator.

As shown in Fig; 2, the knob 4 is arranged within a ring projection 35on the front end of housing I and is slidably mounted upon a sleeve 35supported within an opening in the front wall of said housing. A pin 3]swiveled to the knob 4 by a screw 38 is arranged within the opening insleeve 35 and a spring 39 held under compression between a shoulderformed on the interior of said sleeve and an enlarged head 40 on therear end of said pin serves to yieldinglyhold said head in engagementwith the front end of insulating support l3. The insulating base 5 ofswitch unit 2 is secured to the bottom wall of housing I by screws 4|and 42 (Fig. 1) and is so located that under normal conditions knob 4 isheld in the insulating support l3.

armors position shown in Fig. 2 under the action of spring 39. Ashereinbefore set forth, upon response of the above described overloadmechanism the insulating support i3 moves forwardly under the action ofspring l9, and as is apparent pin 31 moves therewith and causes knob 4to move forwardly with respect to the ring projection 35 on housing I toindicate response of said overload mechanism. Upon inward movement ofknob 4 into the position shown in Fig. 2 insulating support [3 is movedinwardly by the pin. 31 to effect resetting of the overload mechanism.

Knob 4 is also provided with means for manually tripping theaforedescribed overload mechanism to effect defrosting of therefrigerator. Such means comprises an insulating trip member 44reciprocably mounted upon insulating support l3 and secured to the innerend of pin 31. As shown in Figs. 2 and 8, the trip' member 46 has aprojection 45 on the inner end thereof which is located to the left ofspring latch 22. (Fig. 6) and is guided within a recess 45 in the upperface of Upon forward movement of knob 4 out of the position shown inFig. 2 the projection 45 on trip member 4 engages the spring latch 22 torelease the same from the toothed head 35 and insulating support I3 thenmoves forwardly under the action of spring [9 to cause contact 9 toeffect interruption of the motor circuit for defrosting of therefrigerator.

As hereinbeforeset forth the energizing circuit for the driving motor ofthe refrigerator extends through stationary contact 5 and movablecontact B, and as will now be set forth the fluid condition responsiveunit 3 acts upon said movable contact to effect cyclic operation of therefrigerator.

The fluid condition responsive unit 3 includes a bellows 48 secured tothe rear wall of housing 5 and having a communicating pipe extension 49on the rear end thereof. The pipe 49 may be connected to the lowpressure side of the refrigerator to provide for operation of thebellows by pressure in that part of the apparatus, or it may contain anexpansible gas and be arranged at a point contiguous to therefrigerating apparatus where the temperature and consequently thepressure within the pipe and the. bellows varies in accordance withoperations of. the refrigerator. The front end of bellows 48 cooperateswith a pivoted lever 50 having an adjustable spring 5| associatedtherewith which opposes expansive movements of the bellows, and saidlever has a snap operating mechanism associated therewith for effectingoperation of the movable contact 8.

More specifically lever 55 is pivotally mounted upon a pin 52 carried bya U-shaped bracket 53 fixed to the bottom wall of housing I by screws54. Said lever has a stirrup 55 fixed to the rear face thereof whichbears against the outer end of bellows 48 and carries a snap operatingmechanism comprising a pair of oppositely arranged U-shaped members 55and 51 operatively connected by a tension spring 58. As shown in Figs.2, 4 and 5, the side arms of members 55 are pivoted at 59 upon spacedlegs 55-50 associated with stirrup 55, while the side arms of member 51are pivoted at 5| upon spaced legs 52-52 associated with said stirrup.Also as shown in these figures the side arms of bracket 53 are eachprovided with a pair of spaced pins 53-43 for engaging member 51 onopposite sides thereof and said bracket is also provided with a fixedstop 54 for limiting movement of member 55 in' one direction and anadjustable stop 55 for lim-' iting movement thereof in an oppositedirection. The free end of member 56 cooperates with an insulating strip66 slidably mounted within a slot in the upper face of insulating base5, and as shown in Fig. 9 the front end of said strip is operativelyconnected to contact 6 at 61.

The operation of the aforedescribed fluid condition responsive unit willnow be more fully described. With lever 56 in the position shown in Fig.2 member 51 is held in a position wherein the axis of spring 56 islocated to the left of the pivot 56 of member 56 and said spring thusacts to hold member '56 in engagement with its associated stop-65. Withmember 56 in this position movable contact 6 engages its cooperatingstationary contact 6 to establish an energizing circuit for therefrigerator driving motor as hereinbefore set forth. With the drivingmotor in operation the temperature within the refrigerator ,decreasesand upon a predetermined temperature drop determined by the degree ofcompression of spring 5| bellows 48 permits lever 50 to move inwardlyunder the action of said spring towards the position shown in Fig. 5.During such inward movement of lever 56 the pins 63 on bracket 53 causethe member 51 to assume a position wherein the axis of spring 56 islocated to the right of the pivot 59 of member 56, andsaid spring thenacts to move member 56 with a snap action from the position shown inFig. 2 into the position shown in Fig. 5. Upon movement of member 56into the position shown in Fig. 5 insulating strip 66 is moved forwardlyto disengage movable, contact 6 from stationary contact 6 for stoppingof the refrigerator. The temperature within the refrigerator thenincreases and upon a predetermined temperature increase bellows 46 moveslever 56 forwardly against the action of spring 5| into a positionwherein the pins 63 on bracket 53 cause member 51 to assume a positionwherein the axis of spring 58 is located to the left of the pivot 56 ofmember 56. Spring 58 then returns member 56 with a snap action into theposition shown in Fig. 2 and contact 6 reengages stationary contact 6 toeffect restarting of the refrigerator.

As will now be set forth, spring 5| has a shop adjustment and a user'sadjustment associated therewith for determining the temperature valuesat which the refrigerator is started and stopped. As shown in Fig. 2,the front end of spring 5| engages a nut 66 which is threaded into oneleg of a U-shaped bracket 66 slidably mounted within a channel 16 in thebottom wall of housing I. The other leg of. bracket 66 has a threadedopening therein for receiving an enlarged screw threaded portion II onthe inner end of sleeve 36 which abuts a washer I2 mounted in the frontwall of housing As hereinbefore stated, knob 4 is movable axially uponthe sleeve 36, and as shown in Fig. 10 said sleeve is provided with flatside faces which engage within the opening in knob 4 to lock said sleeveand said knob against relative rotation. Also as shown in Figs. 2 and10, the inner face of knob 4 is provided with a channel 13 for receivinga projection 14 on the front face of housing and a stop 15 within saidchannel cooperates with the projection 14 to limit rotation of said knobin opposite directions. As is apparent from the foregoing, the degree ofcompression of spring 5| may be varied by adjusting nut 66 with respectto bracket 63, and in practice this nut is shop adjusted with sleeve 36in a given angular position to provide for starting and stopping of therefrigerator at predetermined temperature values to effect what may betermed normal cycles of operation of the refrigerator. By rotating knob4, the screw H on sleeve 36 varies the position of bracket 66, and thedegree of compression of spring 5| is thus changed to vary thetemperature values at which the refrigerator is started and stopped, orto effect what may be termed non-normal cycles of operation of therefrigerator.

As shown in Fig. 2, the biasing spring i6 associated with insulatingsupport I3 is held under compression between said support and a thimble16 fixed within an opening in nut 66. Also as shown in Fig. 2, theaforedescribed mechanism is enclosed within the housing by a cover 11which is secured to said housing by a screw 16.

Referring now to Fig. 11, the same illustrates a modified form of manualcontrol means including a knob 76 fixed to the sleeve 36,and a knob 86fixed to the pin 31. As is apparent, knob I9 -when rotated serves toadjust the sleeve 36 to vary the temperature values at which therefrigerator is started and stopped. On the other hand, the pin 31 ismovable axially by the knob 66 to effect control of the switch unit 2 inthe manner hereinbefore set forth, and to also indicate tripping of theaforedescribed overload mechanism.

What I claim as new and desire to secure by Letters Patent is:

1. In a controller for electric refrigerators, in combination, a circuitcontrolling device, fluid condition responsive means for effectingcyclic operation of said device, thermal overload means responsive toeffect circuit opening operation of said device, and a manual controlelement rotatable to vary the operating characteristic of said firstmentioned means and movable axially to effect resetting of said thermaloverload means upon response thereof.

2. In a controller for electric refrigerators, in combination, a circuitcontrolling device having thermal overload means associated therewithresponsive to efiect circuit opening operation thereof, fluid conditionresponsive means for effecting cyclic operation of said device and amanual control element rotatable to vary the operating characteristic ofsaid fluid condition responsive means, said manual control element beingalso movable axially to effect operation of said device independently ofsaid fluid condition responsive means and to effect resetting of saidthermal overload means upon response thereof.

3. In a controller for electric refrigerators, in combination, a circuitcontrolling device having thermal overload means associated therewithresponsive to effect circuit opening operation thereof and having fluidcondition responsive means associated therewith for effecting cyclicoperation thereof, and a manual control element rotatable to vary theoperating characteristic of said last mentioned means, said controlelement being also movable axially out of a given normal position uponresponse of said overload means and being adapted upon return to saidnormal position to reset said overload means.

4. In a controller for electric refrigerators, in

of said refrigerator, and movable axially to efiect resetting of saidoverload protective means- 5. In a controller for electricrefrigerators, in combination, a circuit controlling device havingthermal overload means associated therewith responsive to effect circuitopening operation thereof, fluid condition responsive means foreffecting cyclic operation of said device, said means having a manualcontrol element associated therewith rotatable to vary the operatingcharacteristic thereof, and means for moving said manual control elementinto a given position to indicate response of said thermal overloadmeans and for also eiiecting resetting of said thermal overload means bymovement of said manual control element out of such position.

6. In a controller for electric refrigerators, in combination, anenclosing casing, a circuit controlling device mounted within saidcasing and having thermal overload means associated. therewith foreffecting circuit opening operation thereof, a fluid conditionresponsive device also mounted within said casing and associated withsaid circuit controlling device to effect cyclic operation thereof, anda pair of concentrically arranged adjusting parts mounted upon saidenclosing casing, one of said adjusting parts being associated with saidfluid condition responsive device and being rotatable to vary theoperating characteristic thereof and the other of said adjusting partsbeing associated with said circuit controlling device and being movableaxially to trip said thermal overload means and to effect resettingthereof.

7. In a controller for electric refrigerators, in combination, a circuitcontrolling device, thermal overload means associated therewithresponsive to effect circuit opening operation thereof, fluid conditionresponsive means for effecting cyclic operation of said device andadjusting means inarmors eluding a manual control element movable in agiven plane to vary the operating characteristic of said fluid conditionresponsive means, said control element being also movable in anotherplane to effect operation of said device independently of said fluidcondition responsive means and to eifect resetting of said thermaloverload means upon response thereof.

8. In a controller for electric refrigerators, in combination, a circuitcontrolling device, thermal overload means associated therewithresponrsive to efiect circuit opening operation'thereof, fluid conditionresponsive means for efiecting cyclic operation of said device and apair of concentrically arranged adjusting parts, one of said adjustingparts being movable in a given plane to vary the operatingcharacteristics of said fluid condition responsive means and the otherof said adjusting parts being movable in a different plane to effectoperation of said device independently of said fluid conditionresponsive means and to also effect resetting of said thermal overloadmeans upon response thereof. 9. In a controller for electricrefrigerators, in combination, a circuit controlling device, thermaloverload means associated therewith responsive to efiect circuit openingoperation thereof, fluid condition responsive means for effecting cyclicoperation of said device and adjusting means for varying the operatingcharacteristic of said fluid condition responsive means, said adjustingmeans including a manual control element movable into a given positionto effect circuitopening operation of said device at will, said elementbeing also movable into said given position to indicate response of saidthermal overload means and being movable out of such position to effectresetting of said thermal overload means. CLARENCE W. KUHN.

